Hammer actuator mechanism



Nov. 4, 1969 MARUM HAMMER ACTUATOR MECHANISM 2 Sheets-Sheet l Filed Nov. s, 1967 DB m U au D U D Rw w m V/ 0 4 W A ma Y B Nov. 4, 1969 H. MARUM HAMMER ACTUATOR MECHANISM 2 Sheets-Sheet 2 Filed Nov. S, 1967 VENTOR HELMUT/%RUM %f fl ATTORNEY United States Patent Office 3,476,229 Patented Nov. 4,, 1969 U.S. Cl. 197-16 4 Claims ABSTRACT OF THE DISCLOSURE A typewriting machine having a carriage which moves by increments after each impression to space a page relative to an impression station. An impression hammer operating from the back of the paper is used to press the paper against a type font plate. The type font plate moves to select the particular impression character to be positioned opposite the hamer. A cycle of operation of the hammer is accomplished by a drive device which has a repeatable cyclic output function program. The cycle is initiated by pressing a key control. The key operates a lever to pull a clutch release link. The clutch release link is disconnected from the lever and key control immediately after the clutch is released, by mechanical action of the drive device independently of the key and lever action, to prevent initiation of a second cyclic Without first release of the manually actuated key.

BACKGROUND OF THE INVENTION Manually operated typewriting devices having a plurality of hammers, each of which carries an individual type font, may be jammed into the impression area by presing a second key before the first has been removed from the impression area. Interlock devices on electrically powered machines prevent such action in the common electric typewriter.

The illustrated embodiment of the invention is designed principally for use with the internationally known proportional spacing typewriter made and sold under the trademark Varityper. In such a machine the type font is carried on a circular segment plate and is caused to move in the impression area for Selection of a particular character, and a single hammer is impressed from the back of the paper to force the paper against that selected type font character. This arrangement makes possible the substitution of font plates for different languages and different styles of type font. (See U.S. 1,973,057 for further details of a printing instrumentality.)

However, it is not permissible that the single impression hammer recycle without first alowing the carriage to move the proper incremental step for the selection of the desired subsequently impressed type font character. It is essential that only one impression be made for each manual actuation of a key.

In prior model typewriting machines wherein the single back hammer is employed, the mechanism for driving the hammer is a spring, as in the present improved structure, but the mechanism for cocking the hammer in the prior machine required the release of the finger actuated key to initiate the cocking mechansm. Hence, the operator could hold the hammer advanced against the type font indefinitely by keeping the key depressed. Such requirement of lifting the key slows the operation. The device of this invention is much faster in operation, and avoids undue complexity. (For comparison, see U.S. 2,030,411 as an example of a prior device for return cocking of a spring operated impression hammer.)

SUMMARY OF THE INVENTION The advantage of this invention is that the cycle of operation of the impression hammer is a completely programmed mechanical function which is ndependent of human vicissitude.

A cyclic program for operating the hammer and returning it to a cocked position is advantageous, but would be completely rendered useless were it possible to recycle the device unintentionally. Therefore, another advantag of this invention is the provision of an initiating device for starting the cycle, with part of the cycle being a means for nullifying the initiation control in order that the cycle be required to end and the initiating device reestablished before a second cycle can begin.

DESCRIPTION OF THE DRAWINGS FIGURE 1 is a top plan view of an office composing machine employing a single impression hammer placed to strike the back of a page and press it into a font plate.

FIGURE 2 is an exploded and schematic illustration of the manual initiating key and extensible control apparatus, with a power clutch and mechanical programming structure for operating the illustrated hammer, which is shown in its cocked position.

FIGURE 3 is a top plan view of the mechanical program device and the spring 'barrel clutch which provides power to the program device.

FIGURE 4 is an elevation view of the apparatus illustrated in FIGURE 3.

FIGURE 5 is a detail section of the interconnection device between the impression hammer and cocking de- Vice.

DESCRIPTION OF PREFERRED EMBODIMENT The FIGURE 1 of the drawings is provided in order to relate the parts shown in FIGURE 2 into an understandable, workable environment. Although the principles of this invention are applicable to various types of typewriting machines, a differential spacing typewriter 10 internationally known by the trademark Varityper is used as an illustration of the invention.

A carriage 12, which carries roller 14 and 15 for paper holding and advancing, is mounted to shift laterally across the machine in order to carry paper relative to an i-mpression station.

The impression station of the illustrated machine is created by a rotatable anvil 17 and a Striking impression hammer 18. The anvil 17 will hold a type font in printing position directed toward the hammer. This is standard construction well known by those skilled in the typewriting art.

The construction of FIGURE 1 sets up an environment in which the invention is useful. The FIGURES 2-4 illustrate the preferred embodiment of the actual apparatus. The hammer 18 is shown in the position that it assumes ready to strike upon release by actuation of a key 19. Key 19 is a typical key from the keyboard of the machine shown in FIGURE 1. The same operation takes place for each character key.

The hammer 18 is pivotable about a pivot support 20. A tail lever 21 and a heavy actuating spring 22 provide a lever force to pivot the hammer 18 about the pivot 20.

The hammer 18 is returned, after a forward stroke, by means of a cocking lever 29. The cocking lever 29 is interconnected with the back of the hammer 18 in the area illustrated in the broken-away portion. The lever is able to follow the movement of the hammer 18 by means of an eccentric bushing. Cocking lever 29 is pivotally mounted on a fixed pivot 30, and hence requires a universal interconnection with hammer 18.

The universal interconnection is obtaned by means of an eccentric drive bushing 31 interacting with a socket bushing 33. Drive bushing 31 is composed of an eXterior concentric bushing 31A carried by lever 29, and a threaded center shaft 31B. A drive pin 31C extends from the center shaft eccentric from the shaft axis. A loek nut holds the shaft in any selected rotaray position for adjustment of the pin eccentricity.

Socket bushing 33 is mounted across the hammer 18 with a portion thereof exposed. A cross Opening 33A is dimensioned to receive pin 31C in a sliding fit.

As the lever 29 elevates, the bashing 33 rotates and slides to the alignment of the pin 31C, and because the hammer moves about center 20, the pin 31C will reciprocate in the Opening 33A.

The cocking lever 29, after being actuated to draw the hammer 18 to its cocked position, is held by a trigger lever 32. Trigger lever 32 and cocking lever 29 have an interlock area 34 enabling the trigger to hold the cocking lever in a releasable grip. The trigger is pivotally mounted on a pivot 36 and urged into the lock holding condition by means of a spring 37.

The combination of the spring powered hammer 18, a cocking lever 29 for driving the hammer against the spring power, and trigger 32 for releasably holding the hammer in the cocked position is an operative group requiring only control and power actuation to render the group fully operative.

A cyclic program device 40 provides the operations of power and trigger control for this purpose. The program device 40 includes a prime source of power in the form of motor 41. A shaft 42 from the motor carries a gear 43 which in turn drives a spring clutch 44 of a common known type. The spring clutch has a contact end 45. An obstruction in the path of the contact end 45 will prevent power transmission. Release of co-ntact end 45 enables power to be transnitted.

A shaft 46 extending from the clutch 44 carries a cam 47 thereon. In FIGURE 2 the cam 47 is ottset out of line with the clutch 44 for the purpose of Opening the drawing to illustrate the parts. Reference number 46 has been placed on both ends of the broken shaft to indicate its continuity.

A shaft 49, later-ally spaced from shaft 46, carries crank levers 51, 52 and 53. The levers 51 and 52 provide the power for cocking the hammer 18, and the control action for release of trigger 32. All directions of rotation, in describing levers 51-53, will be with respect to the view in FIGURE 2. A rod 55 interconnects one end of crank lever 51 and the Cooking lever 29. The rod 55 has a loop end 56 which encompasses a pin 57 carried by the cocking lever 29. Loop end 56 is eapable of forward movement away from the pin without actuating the pin. This condition is illustrated in FIGURE 2 indicating that the crank lever '51 is in its ready position with the loop end of rod 55 advanced away from the pin 57.

The crank lever 51 is urged in the connter-clockwise direction by means of a spring 58. The opposite end of the crank lever 51 carries a cam follower 60. The follower 60 is positioned to ride the surface of cam 47 as seen best in FIGURES 3 and 4. In FIGURE 4 follower 60 is shown positioned on the low side of the cam adjacent the shoulder Connecting to the high side of the cam. It is desired to space the end of loop 56 from pin 57 at the beginning of the cycle to assure that pin 57 is not restricted when the hammer is released for impresson actuation.

The crank lever 52, mounted adjacent to the lever 51, has an end 62 for attachment of a rod, and a cam follower end 63. A rod 64 interconnects crank lever 52 and trigger 32. The rod is connected to the trigger 32 at point 65 which is below the pivot 36, and therefore Will cause the trigger 32 to rotate counter-clockwise as seen in FIGURE 2 whenever rod 64 is pulled toward the cyclic program device 40.

The cam 47 carries an actuation pin 66, and as better seen in FIGURES 3 and 4, the cam follower end 63 of lever 52 is positioned to be contacted and actuated by the pin 66 as the cam 47 rotates. The position of the cam 47 illustrated in FIGURE 4 indicates that the pin 66 must rotate through substantially 15 -30 of its cycle before 4 reaching the cam follower end 63. In FIGURE 4, the follower end 63 lays` in front of the crank lever 53, and the relative position is therefore better seen in FIGURE 3.

As thus far described, the cyclic program device, whenever spring clutch 44 is free to drive the cam 47, will first actuate trigger 32 to release the interlocking area 34. Then, spring 22 may actuate the hammer 18 into an impression blow. The rod 55 commences a retraction movement before the actual release actuation of trigger 32. Advancement of the hammer 18 will cause pin 57 to advance into the loop 56 and close the gap that was previously created. Therefore, the hammer strikes its home position to make an impression, it is immediately actuated to begin its return movement as rod 55 draws upon the pin 57 and returns the interlocking area 34 to its locking condition.

This cycle of hammer release and Wthdraw to cocking position Will take place for each revolution for cam 47, and therefore unless cam 47 is controlled and limited to one revolution, the hammer 18 will cycle repeatedly and prevent useful controlled work. Crank 53 provides this control function.

A pawl 70 is pivotally supported on the shaft 49 and has a contact end 72 which provides a retractable obstruction for contact actuation of spring clutch contact end 45. In FIGURE 2 the pawl 70 is shown in the lock position wherein the end 45 is held by the contact end 72 and therefore holds the cyclic program device 40 in an inactive position.

In normal operative relationship, when the spring clutch 44 is held inactive as illustrated in FIGURE 2, there would be no loop extension as shown in FIGURE 2.

In the type of machine as illustrated in FIGURE 1, as a key 19 is actuated, a bail 75 is lifted in order to perform several functions. For the purposes of this invention, as seen in FIGURE 2, actuation of the bail 75 operates through levers 76 and 77 to pull a rod 78 in the direction of the arrow. A spring 80 urges the rod 78 both upwardly and to the right against the pull created by the levers 76 and 77.

The control to prevent 'repeat eycling is a linkage means from the key which includes the rod 78 as a first section, and the pawl 70 as a second section. The pawl 70 is slotted by an L slot 82 having a Vertical and a lateral portion. As illustarted in FIGURE 2, the L is reversed. When the rod 78 is in the vertical section as illustrated in FIGURE 2, 'any action to pull the rod 78 will cause a corresponding swinging movement of the pawl 70 to draw the contact end 72 from the spring clutch contact end 45. However, if the rod 78 is moved down to the lateral section of the L slot 82, the pulling action of rod 78 is disconnected, in effect. It is ineffective to operate pawl 70. Hence, the rod 78 and pawl 70 may be considered to be joined by an extensible interconnection wherein the Sections are physically shiftable between first and second relative positions, the first position being a force transmission position for transmitting control movement from the key to the clutch 44, whereas the second position is a disconnect for release of the clutch. When the clutch is released it will not transmit driving force.

The crank lever 53 has a cam end 85 and a follower end 86. Follower end 86, as seen in FIGURES 3 and 4, is positioned to be contacted by the pin 66 immediately after pin 66 leaves the follower end 63 of the trigger releasing crank lever 52. The cam end 85 of the crank lever 53 is positioned to strike rod 78 and drive it downwardly against the urge of spring 80. The rod 78 is moved a sufi'icient vertical distance that it will drop down to the lateral section of the L slot 82. In the lateral section, the drive between the extensible interconnected parts is disconnected, in eect. The drive of the rod 78 to the disconnect position takes place immediately after trigger actuation.

The cam 47, after trigger actuation, has produced all its cycle functions except to finish drving the crank lever 51 back to its starting position. Therefore, there is no longer need for the pawl 70 to remain withdrawn, and its immediate return to interference position where it can nterfere with movement of the contact end 45 assures that the spring clutch 44 will be brought to a halt at the end of a single revolution.

The output function driven by the clutch 44 provides a cycle of operation which first releases the hammer 18 for spring actuation and thereafter operates the cockng lever to draw the hammer to the cocked position. The manually operable key operates the extensible interconnection to begin the drive of the cyclic program device 40 which is the output function in this embodiment, and that program device in turn causes the disconnect of the control linkage in order that no repeat of hammer actuation is .possible until the key is released to allow the reset of the extensible interconnection.

Whereas the present invention has been shown and de scribed herein in what is conceived to be the best mode contemplated, it is recognized that departures may be made therefrom within the scope of the invention which is, therefore, not to be limited to the details disclosed herein, but is to be afforded the full scope of the invention as hereinafter claimed.

What is claimed is:

1. In a typewriting machine having an impression hammer, a spring urging said hammer into an impression impact position, and a cocking lever for drawing said hammer out of impact position to a cocked position, the improvement in single impression key operation device, comprising:

a prime mover, a clutch driven by said prime mover, an output function driven by said clutch, said output function providing a cycle of operation which first releases said hammer for spring actuation and thereafter operates said cocking lever to Withdraw said hammer to said cocked position;

a manually operable key;

a control linkage means from said key for operating said clutch through one cycle only of said output function for each key actuation, said control linkage including first and second Sections joined by an extensible nterconnection Wherein the Sections are physically shiftable between first and second relative positions, said first position being a force transmission position for transmitting control movement from said key to said clutch, said second position being a disconnect for release of said clutch; and

said output function including means to shift said extensible interconnection from said first to second condition prior to completion of one cyclce of said output function.

2. A typewriter, comprising:

an anvil and a hammer, means mounting said hammer to operate in a cycle from a rest position into contact with said anvil and return, said hammer and anvil bearing mutually compatible surfaces for creating an impression under impact;

a prime mover power means;

clutch means having a first condition wherein said power means is connected to drive said hammer, and said clutch means having a second condition of disconnect from said hammer;

a drive link normally connected in driving relation to .said clutch means, said drive link movable in a clutch .actuation movement to place said clutch means in said first condition, and means for urging said clutch means to said second condition;

a plurality of type keys, each connected to actuate said drive link in said clutch actuation movement in response to key operation;

disconnect means driven by said power means through said clutch means in said -first condition for disconnecting said drive link from said driving relation with said clutch means after clutch actuation and before one full hammer cycle; and

means operable only under full drive link release from said keys for restoring said link to its said normal driving condition with said clutch means.

3. In a typewriter as defined in claim 2:

a trigger release of said hammer and a hammer cocking drive operating a sequentially; and

a drive action which physically shifts said drive link out of drive connection with the clutch means, said drive action taking place after trigger release and before finish of the hammer cocking.

4. In a typewriter as defined in claim 2:

said clutch means being a spring clutch with a spring end release;

a swingable catch having a first position to contact said spring end to stop the clutch action, and a second position out of contact position to allow clutch powe'r transfer; and

said swingable catch having a hook surface for engagement by said drive link, said link and surface being physically shifted to said second position by lateral shifting of the drive link under the action of said disconnect means.

References Cited UNITED STATES PATENTS 1,918,300 7/1933 Trego 197-49 2,051,112 8/ 19.8 6* *Spaloss 197-49 2,059,215 11/1936 Dreher 197-114 XR 2,638,199 5/1953 Schremp 197-17 2,858,924 11/1958 Young 197-17 2,919,002 12/ 1959 Palmer 19-7-16 3,306,417 2/ 1967 Gassino et al. 197-47 EDGAR S. BURR, Primary Examiner U.S. Cl. X.R. 

